Not Applicable.
Not Applicable.
This invention relates generally to the field of laboratory vessels. More specifically, this invention relates to a laboratory container or vessel for the culturing of tissues, cells, microorganisms and the like that maximizes the fluid phase and solid surface growing area by excluding gaseous interchange with the external environment.
Specialized vessels or containers, known generally as cell culture vessels, are used in the laboratory for a variety of purposes. Typically, however, such containers are used to grow rapidly multiplying cells in a culture medium or agar, either in fluid phase or adhered to an interior surface of the container. Types of such specialized vessels include non-static vessels, such as roller bottles and spinner flasks, as well as static vessels, such as petri dishes and tissue flasks. Roller bottles are containers which may be placed into a machine to gently agitate the contents thereof and to provide a continuous bathing of cells growing therein. Spinner flasks are designed to similarly agitate their contents through use of a moving paddle which continuously suspends cellular material in the culture medium. Static vessels, on the other hand, are designed such that their contents are not agitated but rather remain relatively static.
Each of the above types of vessels is designed to be incubated in temperature, humidity and gas controlled environments to facilitate maximum cell or tissue growth. Generally, a layer of cell culture medium or agar covers the growing surface. The portion of the vessel not utilized as a growing surface encloses the interior gaseous environment which surrounds the cell culture.
Cells, tissues, microorganisms and the like typically are introduced into the interior of cell culture vessels through an opening in the vessel. After introduction, the opening may be capped as desired such that the interior of the vessel is closed to the external environment. A cell culture vessel which is standard in the art is disclosed in U.S. Pat. No. 5,924,583. The ""583 patent discloses a plastic cell culture vessel having a wide neck which has an opening at one end thereof. The opening opens to the external environment and facilitates access to the interior of the vessel. A screw cap is adapted to close off the opening when such access is no longer desired.
Conventional vessel designs such as those discussed above expose the growing cells to O2 in the external environment. A steady source of environmental O2 is believed to be important for healthy cell growth. It is difficult, however, to control the pH of the culture medium in such conditions. Therefore, it is generally believed to be necessary to grow cells in the presence of CO2 in order to maintain the medium in a pH range that is optimal for cell growth. Despite the generally accepted belief regarding the importance of environmental O2 for cell growth, there is a growing body of evidence that this underlying assumption is incorrect and, in fact, the amount of O2 dissolved in the culture medium itself is sufficient to sustain cell growth to relatively high densities. Additionally, studies indicate that pH may be maintained through use of Hepes buffer.
The types of vessels described above suffer from a number of drawbacks. First, non-static vessels are generally fairly labor intensive requiring frequent monitoring of the agitation of their contents. Secondly, both non-static and static type devices are typically unreliable for the maintenance of sterility. It is standard belief in the art that it is desirable to have a cell culture vessel with an access opening or port that is sufficiently large to permit access to the entire bottom surface of the vessel. This allows cells to be harvested from the vessel walls and minimizes interference upon pouring from the vessel cells that have been cultured therein. Further, desired gas interchange between the internal environment and the external environment of the vessel occurs through the opening in the vessel when the cap is loosened or removed. Vessel designs having such a large access port generally are referred to as xe2x80x9copenxe2x80x9d, indicating that they must be opened at some time during use to allow access and/or gaseous interchange. However, this type of direct gaseous communication with the ambient environment, creates the possibility of bacterial contamination and renders these systems unreliable for maintaining aseptic or sterile conditions. When contamination with ambient elements occurs, the contents of the vessel must be rejected, thereby causing a significant loss of data and time.
Another drawback of the cell culture vessels discussed above is that the vessels often do not maximize use of laboratory space. In laboratory practice, it is quite common to arrange or stack several cell culture vessels in a single chamber, such as an incubator, to maximize the use of available space. The shape of individual vessels is crucial with regard to the number of vessels which may be positioned in a single chamber. However, the shape of many of the cell culture vessels described above renders them difficult to stack. Accordingly, these vessels fail to maximize the use of the available space in laboratory chambers.
Despite these drawbacks, little effort has been devoted to the development of cell culture vessels that are designed to grow cells in either a pure fluid phase or solid surface environment which eliminates gaseous interchange with the external environment, although such a vessel would dramatically decrease sterility concerns. There are notable exceptions, however. For instance, one alternative to plastic culture vessels are gas permeable plastic bags such as those disclosed in U.S. Pat. Nos. 3,941,662, 4,142,940 and 4,829,002. Additionally, fermentation vessels that were previously used for microbial culture have been adapted for cell growth. Further, various cell culture systems have been developed that employ hollow fiber cartridges for cell growth. Fiber cartridge systems typically include a housing and a plurality of capillaries or hollow fiber membranes which contain selectively permeable walls through which cell culture media may diffuse. Examples of such systems are disclosed in U.S. Pat. Nos. 5,763,261, 5,424,209 and 4,889,812.
Each of these alternative culture vessels has been developed to fill a specific niche that could not be satisfied by the conventional plastic culture vessels typically used in the art. Unfortunately, however, most of the advantages that are provided in the simple, flat-surfaced plastic cell culture vessels are lost when the vessels are modified in any one of the above-listed ways.
Accordingly, there is a continuing need in the cell culture industry for an improved cell culture vessel which produces increased cell growth efficiency. Additionally, there remains a need for a modified cell culture vessel that maximizes the fluid phase and solid surface growing area by excluding gaseous interchange with the external environment while maintaining the advantages provided by flat-surfaced plastic cell culture vessels. Further, there is a need for a cell culture vessel that allows simple, inexpensive, large-scale anchorage dependent culture of tissues, cells and/or microorganisms, either in fluid phase or adhered to the interior surface of the container, which is of a shape conducive to stacking one upon another.
Accordingly, in one of its aspects, the present invention provides an improved cell culture vessel having quality construction for culturing cells, tissues, microorganisms and the like.
In a further aspect, the present invention provides a cell culture vessel which produces increased cell growth efficiency.
In another of its aspects the invention provides a cell culture vessel which maximizes fluid phase and solid surface growing area as it may be completely filled with culture medium.
In still another of its aspects, the present invention provides a cell culture vessel that is designed to allow medium and cells or tissues to be added or removed while simultaneously excluding the external gaseous environment.
In yet another of its aspects, the present invention provides a cell culture vessel which eliminates the need to grow cells in CO2 incubators to maintain gas and humidity control.
In a still further aspect, the present invention provides a cell culture vessel of a shape which maximizes use of laboratory space by permitting a plurality of vessels to be stacked upon one another.
According to the present invention, the foregoing and other objects are achieved by a vessel for growing tissues, cells and/or microorganisms which comprises a body defining an interior chamber and at least one aperture in the body for permitting fluid communication between the interior chamber and an external environment. The body includes top and bottom walls each having a planar portion and a tapered portion. The tapered portion of the top wall tapers outwardly and downwardly from the planar portion thereof to define an outer periphery. The tapered portion of the bottom wall tapers outwardly and upwardly from the planar portion thereof to define an outer periphery. The outer peripheries of the respective walls are aligned with and coupled to one another. The aperture includes a closure component coupled thereto for closing off the interior chamber from the external environment.
The present invention further provides a cell culture vessel having a body which defines an interior chamber and at least one aperture in the body for permitting fluid communication between the interior chamber and an external environment. The body includes spatially removed first and second body walls and at least one side wall. The first and second body walls are generally planar and are substantially parallel to one another with each body wall defining an outer periphery thereof. The side wall has a top edge and a bottom edge and is positioned such that the top edge aligns with the outer periphery of the first body wall and is coupled thereto and the bottom edge aligns with the outer periphery of the second body wall and is coupled thereto. The aperture in the body includes a closure component coupled thereto for closing off the interior chamber from the external environment.
Additional aspects of invention, together with the advantages and novel features appurtenant thereto, will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned from the practice of the invention. The objects and advantages of the invention may be realized and attained by means, instrumentalities and combinations particularly pointed out in the appended claims.